The Effect of PD-1/PD-L1 Inhibitor and Statin Combination Therapy on Overall Survival and Gastrointestinal Toxicity.

Objectives: Immune checkpoint inhibitors (ICIs), such as programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1) inhibitors, have been approved to treat a variety of cancers. Recently, studies have suggested that ICIs and statins are synergistic. However, the addition of statins to ICI therapy may increase the risk of gastrointestinal immune-related adverse events (irAEs). We investigated the effect of combination therapy with PD-1 and/or L1 inhibitors and statins on overall survival and gastrointestinal irAEs.

Methods: We reviewed the charts of patients with select cancers who received PD-1 and/or PD-L1 inhibitors and statins. The incidence of gastrointestinal irAEs and overall survival were compared with that in a matched control group of patients who received PD-1 and/or PD-L1 inhibitors without statins.

Results: Of the 823 patients in the statin group, 707 received PD-1 inhibitors, 86 received PD-L1 inhibitors, and 30 received both. Patients taking any statins (10.8%) and those taking high-intensity statins (15.8%) had higher rates of gastrointestinal irAEs than patients not taking statins (8.7%; P=0.046 and 0.006, respectively). Compared with the nonstatin treatments, statin use was associated with improved overall survival for patients taking PD-1 inhibitors (P<0.001) and for patients with (P=0.021) and without (P<0.001) gastrointestinal irAEs.

Conclusions: Synergism of statins with PD-1 and PD-L1 inhibitors continues to be a developing field of interest. Our data demonstrate the survival benefit of combination therapy with PD-1 and/or PD-L1 inhibitors and statins, warranting further investigation.